1. Field of the Invention
The present invention relates to a data processing system and method, a transmission apparatus and method for controlling the transmission apparatus, and a band control apparatus and method for controlling the band control apparatus. More particularly, the present invention relates to a technology suitably used to allocate an optimum transmission path band.
2. Description of the Related Art
In an information communication network, such as the Internet, information is divided into units called packets and is transmitted processing of packets in a network, basically, a processing method operating on a first-come, first-served basis, which is called a best effort method, is performed to transmit the packets. However, in such a processing method, since all packets are handled equally, a sufficient transmission path band cannot be guaranteed for multi-media traffic necessitating real-time transmission of data, such as audio and images. For this reason, a fixed quality cannot be guaranteed, for example, precise reproduction is not possible in real time on the reception side.
In comparison, in Internet Engineering Task Force (IETF), a resource reservation protocol, such as Resource ReSerVation Protocol (RSVP), is defined as an Internet standard.
Use of RSVP enables a transmission path band necessary for each stream to be allocated before communication is started, and thereby communication in which a fixed quality is guaranteed can be performed.
However, hitherto, when a band reservation function, such as RSVP, has been used from an application (application program), a function of requesting a band reservation has been incorporated for each application. Then, by using only the band needed by an application as a single parameter, a band reservation request for only that band is made to the network.
For this reason, external factors, such as a communication request for each user and currently usable bands of the network, are not taken into account. Therefore, regarding band reservation regulation, optimization in which these parameters are evaluated comprehensively has not been sufficiently performed.
An example of a wireless standard is IEEE 802.11e. Based on IEEE 802.11a and IEEE 802.11b, which are known standards, IEEE 802.11e has been established as a standard used when performing expansion regarding QoS and security. A dynamic TDMA method has been adopted for access control. The TDMA method is a method in which a transmission path band is shared on a time-division basis, whereas the dynamic TDMA method is a method in which terminals exchange control information with each other, the priority is determined according to the type of data to be transmitted, and efficient data transmission is made possible. In streaming of audio and moving images, since a fixed transmission path band is allocated, interruption of data transmission does not occur, and smooth reproduction is guaranteed.
Furthermore, for example, in Japanese Patent Laid-Open No. 11-98152, resources of the network are reserved for an optimum communication band calculated based on the band desired by a user and the network bands that can be used at that time. Then, a technology for starting the transmission and reception of the stream of a communication application is disclosed. As a result, it is possible to guarantee as a minimum quality of communication that can be used at that time.
However, in the related art, the transmission path band specified by the user is not determined based on the actual streaming data. For this reason, in some cases, the transmission path band specified by the user may be increased more than is necessary, and there is a possibility that the use efficiency of the line is decreased.